There has been a trend in the mobile phone industry towards giving users the ability to alter the appearance of their phone. One way of adapting the phone's external appearance is to fit a leather sack-like cover over the exterior of the phone. These external covers protect the exterior plastic cover from damage and allow some adaptation of the phone's appearance, however, they significantly increase the bulk and weight of the phone. Another way of adapting the phone's external appearance is to provide user replaceable rigid plastic covers as described in U.S. Pat. No. 6,347,218. The replaceable covers have proven to be very popular and the phone is now becoming a fashion accessory which is worn and/or displayed by a user.
FIG. 1a shows an example of a prior art phone 2 comprising an engine assembly 10 enclosed by a removable rigid plastic front cover 4 and a removable rigid plastic back cover 8. A loose keypad 6 overlies switches 14 (key domes) of the engine assembly 10 and is held is place by the rigid plastic front cover 4 in the assembled phone 2. The components of the prior art phone 2, and the engine assembly in particular, are schematically illustrated in FIG. 2. The engine assembly 10 is in physical connection with the keypad 6 as shown by arrow A. The engine assembly 10 comprises a plurality of keyboard switches 14 electrically connected to a processor 20, a battery 30 electrically connected to at least the processor 20 for power distribution to other circuitry, a SIM card 28 electrically connected to the processor 20, a display 12 electrically connected to the processor 20, a memory 26 electrically connected to the processor 20, radio transceiver circuitry 24 for communicating in a cellular communications network is electrically connected to the processor 20 and an audio part 22 is electrically connected to the processor 20. The audio part 22 provides an electrical signal to the speaker 16 and receives an electrical signal from the microphone 18. The inter-operation of these parts to operate as a cellular mobile phone is well known to persons skilled in the art, who will additionally appreciate that although a GSM compliant engine assembly 10, as in this example, has a SIM card 28 it may not be present in engine assemblies for other cellular communication standards.
FIG. 1b shows an alternative design of covers for the phone 2. In this example, the rigid plastic back cover 8 is permanently attached to the engine assembly 10 and is not removable. The rigid plastic front cover 4 is removable and a loose keypad 6 is located between it and the engine assembly 10 when the phone 2 is assembled.
The rigid plastic covers 4 and 8 are three-dimensional and provide a recognisable shape to the phone. They additionally may protect the engine assembly 10 against damage and water ingress and are easily made by injection moulding. For these reasons rigid covers, and plastic covers in particular, are universally used to enclose the engine assembly 10.
The inventor has realised that it would be desirable to have a greater range of fashionable phones. In particular, the inventor has realised that it would be desirable to allow a user greater choice in adapting the appearance of their phones.